1 research outputs found
Optical Mie Scattering by DNA-Assembled Three-Dimensional Gold Nanoparticle Superlattice Crystals
Programmable assemblies of gold nanoparticles engineered
with DNA
have intriguing optical properties such as Coulomb-interaction-driven
strong coupling, polaritonic response in the visible range, and ultralow
dispersion dielectric response in the infrared spectral range. In
this work, we demonstrate the optical Mie resonances of individual
microcrystals of DNA–gold nanoparticle superlattices. Broadband
hyperspectral mapping of both transmission and dark-field scattering
reveal a polarization-insensitive optical response with distinct spectral
features in the visible and near-infrared ranges. Experimental observations
are supported by numerical simulations of the microcrystals under
a resonant effective medium approximation in the regime of capacitively
coupled nanoparticles. The study identifies a universal characteristic
optical response which is defined by a band of multipolar Mie resonances,
which only weakly depend on the crystal size and light polarization.
The use of gold superlattice microcrystals as scattering materials
is of interest for fields such as complex nanophotonics, thermoplasmonics,
photocatalysis, sensing, and nonlinear optics